Field of the Invention
The invention relates to a heat exchanger comprising a first flow channel for a refrigerant, a second flow channel for a refrigerant, and a third flow channel for a coolant, whereby the first flow channel has a first region for the initial cooling of the refrigerant and a second region for the further cooling of the refrigerant, whereby the refrigerant can flow in a high-pressure phase in the first flow channel and the refrigerant can flow in a low-pressure phase in the second flow channel.
Description of the Background Art
Condensers are used in refrigerant circuits of climate control systems for motor vehicles in order to cool a refrigerant to the condensation temperature and then to condense the refrigerant. This occurs in particular in the case of refrigerants that undergo at least one phase transition from gaseous to liquid in the refrigerant circuit. Condensers routinely have a collector in which a volume of refrigerant can be stored to equalize variations in volume in the refrigerant circuit. As a result, a stable subcooling of the refrigerant can be achieved.
Additional components for drying and/or filtering of the refrigerant are often provided in the collector. The collector is usually disposed on the condenser. The refrigerant that has already flown through part of the condenser flows through the collector. After flowing through the collector, the refrigerant is returned to the condenser and subcooled in a subcooling section to below the condensation temperature.
Condensers are also known in which the refrigerant does not undergo a phase transition. These condensers usually have only one cooling section in which the refrigerant is brought into thermal contact with a coolant.
Furthermore, heat exchangers are known downstream of which an internal heat exchanger is connected after the condensation section and the subcooling section. A collector is thereby disposed between the condensation section and the subcooling section. Whereas in the condensation section and the subcooling section heat transfer occurs between a refrigerant and a coolant, in the internal heat exchanger heat transfer occurs between the refrigerant in two different states, namely, in a high-pressure phase and a low-pressure phase.
A disadvantage of the devices known from the prior art is particularly that during use of CO2 (R744) as the refrigerant high pressures arise within the refrigerant circuit, which stress the heat exchangers known thus far beyond their stress limits.